1. Field of the Invention
The invention relates to injecting a substance into a volume of the body and leaving the substance in the volume temporarily. The invention also relates to occluding the volume by a catheter and means for guiding the catheter to the volume. Such injection is of particular interest in the field of coronary angiography and coronary intervention, and particularly deals with the handling of the substance in the form of a contrast agent. The invention also relates to devices for the handling of contrast agent in the heart during angiographic and intervention procedures.
2. Description of the Prior Art
U.S. Pat. No. 6,021,340 to Randolph et al. has a guiding catheter for the coronary sinus. The guiding catheter of Randolph et al. has bent end portions as shown in FIGS. 8 to 11. This catheter has an occluding means in the form of a balloon 36. None of the bent portions are C-shaped or S-shaped as contemplated by the instant invention. Furthermore, the balloons 36 are disposed on straight portions of the catheter as shown n FIGS. 4 and 7.
An important difference between the device of Randolph et al. and the instant invention is that the bend in the end portion of Randolph's device is adapted for locating a device 70 in a branch 52 off the coronary sinus 50 for detecting electrical activity in the branch 52 off of the coronary sinus 50.
Randolph lacks providing any disclosure to injecting contrast by a second catheter upstream of the occlusion.
Randolph also lacks occluding for the purpose of isolating and removing contrast. The purpose of Randolph's occlusion is to, “stop blood flow through the blood vessel in order to minimize misdirection of the contrast fluid and the dilution thereof which can interfere with fluoroscopic observation of the branch blood vessel.”
US Patent Application Publication No. US 2001/0052345 to Niazi has a catheter to cannulate the coronary sinus. The device of Niazi has an inner catheter 12 and an outer catheter 10. Outer catheter 12 functions more like a guiding sheath, which is known and used in the art for guiding a catheter and which is inserted therein to be guided into a selected position. Therefore, the catheter combination of Niazi is different from the instant invention since it is not provided as a single catheter having a bent distal end for guiding the tip of the catheter.
The catheter pair of Niazi also varies from the instant invention in its purpose. Niazi has the purpose of locating and aiding in locating a pace lead, and the occlusion device 21 of Niazi is not intended for isolation and removal of contrast as is that of the instant invention.
Another difference between the catheter of Niazi and the instant invention is that the bend in the distal end of outer catheter is not particularly C-shaped. As best shown in FIGS. 2-5, the distal end portion appears to have a very particular configuration comprising angles and relative orientations in order to insert the pair of catheters into the coronary sinus via percutaneous insertion through the jugular or subclavian vein as can be understood by FIGS. 7 and 8. Niazi does not show or disclose engaging the coronary sinus with a catheter inserted via the femoral vein as is contemplated by the instant invention.
Furthermore, the device of Niazi does not have a second catheter inserted upstream of the veins for injecting contrast just before suctioning and removal of the contrast.
A related feature of the instant invention is that a volume of a vasculature may be viewed between the coronary arteries and the coronary sinus. This requires the second catheter of the instant invention.
Contrast usage during coronary angiogram or intervention in patients with renal disease is associated with substantial risk of renal failure in 30% of patients with renal disease and up to 50% in patients who have diabetes mellitus and renal failure. This side effect is responsible for long hospital stays and, in some patients, permanent renal damage requiring chronic dialysis. Any intervention that could decrease the amount of contrast exposure to the kidney would substantially decrease the risk of renal complications. It is well known that the amount of dye used in coronary intervention correlates with contrast induced nephropathy.
No procedure is known or currently used for removing contrast from a heart of a patient undergoing a diagnostic or an intervention procedure. Thus it is a primary object of the instant invention to provide a method and apparatus for removing contrast from a vessel of the heart during angiographic and intervention procedures on the heart.
The prevention of renal failure in patients undergoing coronary angiography or intervention by this method will substantially save lives and medical costs. As can be noted by the statistics set forth above, permitting contrast to enter a circulatory system of a patient with underlying renal disease is a major risk factor. The instant invention is a significant advance over the prior art in avoiding such high risk.
Furthermore, it is an object of the present invention to provide more generally a method and apparatus for temporarily injecting a substance into a volume or vessel of the human body for any of several purposes. The purposes include, but are not limited to: injection of therapeutic or medication fluids, diagnosis and/or research by injecting a contrast and imaging the interior of the volume or vessel, or for facilitating imaging of mechanical or chemical procedures in the interior of the volume or vessel.
It is a further object of the instant invention to provide a method and apparatus to accomplish the above objects, wherein the apparatus includes a controller to partially or completely automate the method.